The invention disclosed herein relates to attachments for tow trucks which lift and tow automobiles and other wheeled vehicles behind the tow truck. More particularly, the invention relates to a tow assembly that includes wheel cradles that receive the front or rear wheels of an automobile and lift the wheels and therefore one end of the automobile from the ground surface without engaging other parts of the automobile.
When an automobile is to be towed, the operator of the tow truck must be very careful that a firm connection is made between the tow truck and the automobile, and also to assure that the automobile will not be damaged as it is lifted and towed. For example, the front and rear ends of automobiles typically include bumpers, lights and other decorative objects that are easily scratched, broken or otherwise damaged. Recently, automobiles have been manufactured with wind deflectors or "spoilers" that protrude downwardly from the front portion of the vehicle, and it is difficult to connect the typical towing device to the automobile without damaging one or more of these objects.
In the past, one of the more popular tow attachments for tow trucks has been a flexible sling attached to a tow bar which extends beneath the automobile that is to be towed and extends around the bumper and is lifted with the typical boom and cable of the tow truck. While the flexible sling tends to protect the bumper and other objects from abrasion, etc., a force is applied by the sling to the front spoiler, the bumper, and other objects that it contacts, such that there is a significant hazard of damaging the automobile.
Other type tow assemblies for connection to tow trucks are available which do not require the conventional sling assembly but include wheel engaging structures or "wheel cradles" which engage the front or rear wheels of an automobile to lift the wheels and therefore one end of the vehicle, substantially without engaging any other portion of the vehicle. Typically, these devices include a tow bar connected to the rear of the tow truck, wheel cradles connected to the tow bar, and a boom and winch assembly that has a cable that extends over the rear of the tow truck and is connected to the tow bar to lift and support the tow bar. Examples of these devices are generally disclosed in U.S. Pat. Nos. 3,434,607, 3,690,482, 3,924,763, and 3,897,879.
Some of the problems present in the prior art wheel lift tow assemblies are that the wheel cradles are difficult to mount to the wheels of the automobile that is to be towed, the tow assembly supports the raised wheels of the automobile at a distance so far from the rear of the tow truck that the weight of the vehicle lifted by the tow truck tends to counterbalance the front of the tow truck such that the steerable wheels of the tow truck do not have enough weight applied to them for safe handling. Other problems include retraction and storage of the tow assembly with respect to the tow truck when the tow assembly is not to be used, and the large size and weight of the wheel cradles and their associated elements which makes the wheel cradles difficult to handle by the truck operator.